Asp.net mvc 如何使用ASP.NET MVC 2+;实体
//在这里,我尝试更改外键,但出现了以下异常:“属性'id\u album'是对象的键信息的一部分,无法更改。” fotooadd.id_相册=Convert.ToInt32(格式[“id_相册])强>Asp.net mvc 如何使用ASP.NET MVC 2+;实体,asp.net-mvc,entity-framework,foreign-keys,Asp.net Mvc,Entity Framework,Foreign Keys,//在这里,我尝试更改外键,但出现了以下异常:“属性'id\u album'是对象的键信息的一部分,无法更改。” fotooadd.id_相册=Convert.ToInt32(格式[“id_相册]) 我一直在研究如何做到这一点,但我遇到了困难,我如何进行此更新操作这将对您有所帮助 在foto类中,您没有类似fotooadd.album的导航属性吗?如果你有它,你可以像fotoLoadd.album=\u db.album.first这样设置。。。 [HttpPost] public Ac
我一直在研究如何做到这一点,但我遇到了困难,我如何进行此更新操作这将对您有所帮助
在foto类中,您没有类似fotooadd.album的导航属性吗?如果你有它,你可以像fotoLoadd.album=\u db.album.first这样设置。。。
[HttpPost]
public ActionResult Edit(FormCollection form)
{
// Get movie to update
var id = Int32.Parse(form["id_foto"]);
var fotoToAdd = _db.foto.First(m => m.id_foto == id);
// Deserialize (Include white list!)
TryUpdateModel(fotoToAdd, new string[] { "descricao" }, form.ToValueProvider());
//Here I try to change my foreign key, but i get this exception: "The property 'id_album' part of the key information of the object and can not be changed."
fotoToAdd.id_album = Convert.ToInt32(form["id_album"]);
//file upload
if (Request.Files.Count > 0)
{
int tamanho = (int)Request.Files[0].InputStream.Length;
byte[] arq = new byte[tamanho];
Request.Files[0].InputStream.Read(arq, 0, tamanho);
byte[] arqUp = arq;
fotoToAdd.imagem = arqUp;
}
//Validation
if (String.IsNullOrEmpty(fotoToAdd.descricao))
ModelState.AddModelError("Descrição", "Ops... campo obrigatório");
if (String.IsNullOrEmpty(fotoToAdd.id_album.ToString()))
ModelState.AddModelError("Album", "Ops... campo obrigatório");
if (fotoToAdd.imagem == null)
ModelState.AddModelError("Foto", "Ops... campo obrigatório");
//If success, Update
if (ModelState.IsValid)
{
_db.SaveChanges();
return RedirectToAction("Index");
}
//Else, return view
return View(fotoToAdd);
}